Apparatus for producing sand molds



Nov. 6, 1962 w. A. HUNTER APPARATUS FOR PRODUCING SAND MOLDS 7 Sheets-Sheet 1 Filed March 16, 1960 nvmvrm WILLIAM A. HUNTER ATTY.

Nov. 6, 1962 w. A. HUNTER APPARATUS FOR PRODUCING SAND MOLDS 7 Sheets-Sheet 2 Filed March 16, 1960 INVENTOR. WILLIAM A. HUNTER Nov. 6, 1962 w. A. HUNTER 3,061,899

APPARATUS FOR PRODUCING SAND MOLDS Filed March 16, 1960 7 Sheets-Sheet. 3

INVENTOR aa WILLIAM A.Huu'rR ATTY.

Nov. 6, 1962 w. A. HUNTER APPARATUS FOR PRODUCING SAND MOLDS 7 Sheets-Sheet 4 Filed March 16, 1960 262 INVENTOR. 76 WILLIAM A. HUNTER BY W ATTY.

Nov. 6, 1962 w. A. HUNTER APPARATUS FOR PRODUCING SAND MOLDS 7 Sheets-Sheet 5 Filed March 16, 1960 lrwzu-roz WILLJAM A. HUNTER '5 Nov. 6, 1962 w. A. HUNTER 3,061,899

APPARATUS FOR PRODUCING SAND MOLDS Filed March 16, 1960 7 Sheets-Sheet 6 1 /f 4 I wi 3g, 2 4

I .I 24 lW/l/I/ 22 V//// l w I 226 Hll Ill llllll i I V '4- I l U4 1 156 X i 1 INVENTOR- lsz WILLIAM A. uu'rsn BY m A'rrv.

Nov. 6, 1962 w. A. HUNTER APPARATUS FOR PRODUCING SAND MOLDS '7 Sheets-Sheet 7 Filed March 16, 1960 INVENTOR WILLIAM .HUNTER United States Patent 3,061,899 APPARATUS FOR PRUDUCING SAND MOLDS William A. Hunter, Morton Grove, 11]., assignor to Pettibone Mullilren Corporation, Chicago, [1]., a corporation of Delaware Filed Mar. 16, 1950, Ser. No. 15,285 2 Claims. (Cl. 2220) The present invention relates to the centrifugal casting of molten metals in the production of tubular articles such as pipe sections and has particular reference to the preparation of sand molds designed for use in connection with such centrifugal casting processes. Still more specifically, the invention relates to an apparatus for facilitating the forming of molds and for facilitating the handling of the flasks in which the molds are formed.

The objects of the invention are manifold and, principalamong them is the provision of a novel apparatus for handling flasks prior to, during, and after mold forming operations, in the form of an automatic or semiautomatic machine which is adapted to operate cyclicly in a repetitive manner to mechanically perform various mold-forming operations including the transporting of empty flasks to a ramming station in an upright position from a remote location; the operative placement of deposition of the flasks upon a spinning table; the introduction into the flasks of an inner core pattern or mandrel and of a base pattern; the centering of the flasks upon the spinning table, the alignment and centering of the inner core and base patterns within the flasks; the performance of the spinning operation including the controlled ramming of sand into the rotating mold cavity; the inner core and base pattern draw operations; the transporting of the flasks with the completed molds therein to a location remote from the ramming station; and the discharge of the thus transported flasks from the remote location and the conduction thereof to a spinning and pouring station.

In carrying out this object of the invention, a novel form of flask-orienting mechanism has been devised by means of which empty flasks delivered thereto at a point remote from the ramming station in a horizontal position will, during their travel to the ramming station, become upended so that upon arrival thereof at the ramming station they will be in a vertical position and in vertical alignment with the spinning table, as well as with the inner core and base patterns maintained at the ramming station.

In the production of said molds of the character briefly outlined above, it is desirable that as many handling operations as possible be performed mechanically inasmuch as most of these operations involve the handling of heavy objects and articles, With both skill and physical strength being required for an operator to make consistently acceptable molds. Since molds of this sort must conform closely to specifications with small allowable tolerances, the production of relatively heavy molds invariably entails a large number of rejects due to operator fatigue, particularly at the end of any given working shift. Accordingly, it is an object of the present invention to provide an automatic or semi-automatic machine which will produce molds of uniformly acceptable quality at a rapid rate of production with a minimum of attention on the part of an operator. This being among the principal objects of the invention, another and important object is to provide an apparatus of this sort wherein dual flask transferring operations are effected between the ramming station and the remote location where the empty flasks are supplied to the apparatus and the filled flasks are discharged from the apparatus, such dual transferring operations including the simultaneous passage of flasks in opposite directions between the ramming tation and remote location with the empty flasks proceeding from the remote location to the ramming station and the filled flasks with the molds therein proceeding from the ramming station to the remote location.

Numerous other objects of an ancillary nature, not at this time enumerated, will become readily apparent as the following description ensues.

In the accompanying seven sheets of drawings forming a part of this specification one illustrative embodiment of the invention has been shown.

In these drawings:

FIG. 1 is a fragmentary side elevational view, somewhat schematic in its representation, of a mold producing and handling apparatus constructed in accordance with the principles of the present invention;

FIG. 1a is a sectional view taken substantially along the line la-la of FIG. 1 in the direction indicated by the arrows;

FIG. 2 is a top plan view of the structure shown in FIG. 1;

FIG. 3 is a side elevational view, partly in section, of a combined pattern draw, and flask centering, supporting and spinning mechanism employed in connection with the invention;

FIG. 4 is a sectional view taken substantially along the line 44 of FIG. 3 in the direction indicated by the arrows;

FIG. 5 is a sectional view taken substantially along the line 5-5 of FIG. 3 in the direction indicated by the arrows;

FIG. 6 is a fragmentary sectional view taken substantially centrally and vertically through a rotary flask and mold transfer and upending mechanism by means of which empty flasks are delivered to the ramming station in a vertical position while at the same time the loaded flasks with the completed mold bodies therein are delivered to a transfer station in a horizontal position, and from which transfer station the mold bodies are conducted to the spinning and pouring station;

FIG. 7 is a sectional view taken substantially along the line 7-7 of FIG. 6 in the direction indicated by the arrows;

FIG. 8 is a sectional view taken substantially along the line 8-8 of FIG. 6 in the direction indicated by the arrows;

FIG. 9 is an enlarged fragmentary sectional view taken substantially along the line 9-9 of FIG. 2 in the direction indicated by the arrows;

FIG. 10 is a fragmentary side elevational view similar to FIG. 1 showing the various parts of the mold producing and handling apparatus in a diiferent position; and

FIG. 11 is an enlarged sectional view taken substantially along the line 11-41 of FIG. 9 in the direction indicated by the arrows.

Brief Description Referring now to the drawings in detail and in particular to FIGS. 1, 2 and 10, briefly, the mechanism disclosed in these views is of a cyclicly operable nature and it comprises a lift frame assembly 10 which is positioned in the vicinity of a ramming station R and which has associated therewith a vertically shiftable lift and centering carriage 12. The carriage 12 is movable between the lower position in which it is shown in FIG. 1 and the upper position in which it is shown in FIG. 10. The carriage 12 is movable between its upper and lower positions under the control of an hydraulic piston and cylinder assembly 14. A spinning table 16 is disposed at the ramming station R and is adapted to operatively receive thereon the lower flanged end 18 of a tubular shell flask 2i and, in the lowered position of the carriage 12 as shown in FIG. 1, a series of centering rollers 22 straddle and engage the upper flanged end 24 of the shell flask and serve to center the same above the spining table 16. The carriage 12 also has associated therewith an upper pattern centering and pattern draw assembly which has been designated in its entirety at 26 (FIG. 9) and by means of which the upper end of a tubualr mandrel or inner core pattern 28, which also is operatively seated upon the spinning table 16 and is concentric with the tubular flask 20, is centered above the table. The flask 20 is provided with a pair of spaced medial flanges and 27 which serve as centering devices at the transfer station in a manner and for a purpose that will be described subsequently.

In moving from its lowered position to its elevated position, the flask 20 is released by the carriage but the inner core pattern 28 is retained thereby so that in the elevated position in which it is shown in FIG. 9, the pattern 28 remains suspended preparatory to its reuse during the next succeeding machine cycle in association with a new flask 20.

The spinning table 16 at the ramming station R is mounted for rotation about -a vertical axis under the influence of a fluid motor assembly 30 (see also FIG. 3). The spinning table 16 per se constitutes the subject matter of my copending application Serial No. 39,634, filed on June 29, 1960 and entitled Apparatus for Producing Sa-nd Molds." The fluid motor assembly 30, and also the spinning table 16, constitute elements of a combined lower pattern draw and flask spinning mechanism 32, this mechanism further embodying hydraulic piston and cylinder assemblies 34 by means of which the spinning table 16 may be moved between its elevated operative position and its lowered inoperative position wherein alower or hub pattern 36 carried thereby is withdrawn from the lower open flanged end 18 of the flask 20'.

Positioned adjacent to the ramming station R and on the side thereof remote from the lift frame assembly 10 is a rotary flask and mold transfer and upending mechanism which has been designated in its entirety at 40. The mechanism 4t) is in the form of an oscillatory turret assembly 42 (see also FIG. 5) which is mounted for rotation in opposite directions about a vertical axis on a stationary turret base 44. Projecting horizontally outwardly in opposite directions from the turret assembly 42 are a pair of flask handling jaw assemblies or cradles 46 and 48 respectively, each assembly having associated therewith a pair of releasable flask-clamping fingers 50. The fingers 50 are movable between a closed flask-clamping position and an open flask-releasing position under the control of a fluid operated actuator 52 in the form of a piston and cylinder assembly.

The turret assembly 42 is adapted to be periodically indexed through an angle of 180 under the control of a fluid-actuated motor 54- which is enclosed within the turret base structure 44- (FIGS. 6 and 7).

The two jaw assemblies 46 and 48 are rotatable about a common horizontal axis and they are capable of being rotated in unison throughout an angle of 90 so that an empty flask 20 received in one of the jaw assemblies in a horizontal position at the transfer station T as shown in FIG. l,'may be upended and delivered to the ramming station R in a vertical position, while at the same time, a flask 20' containing a mold which has been spin-formed at the ramming station R may be received by the other jaw assembly in a vertical position and, by a declining operation, delivered to the transfer station T in a horizontal position. The upending operation and the declining operation, referred to above, take place during indexing of the turret 42. The jaw indexing operations are an automatic function of the turret indexing operations.

At the transfer station, the mold-containing flasks 20 are released by the jaw assemblies and deposited in a cradle 58 associated with a transfer carriage 60 which maintains them in their horizontal position and which conducts them from the transfer station and deposits them on a pair of inclined ramp-forming rails 62 by means of which, under the influence of gravity, the flasks may be transported to a remote spinning and pouring station SP to produce the metal pipe casting by known centrifugal casting operations. From the spinning and pouring station the flasks with the filled molds therein are transported to a shakeout station where the cast pipe sections are removed from the molds and the empty flasks are deposited in a horizontal position on rails 64 for return by gravity therealong to the transfer station, at which station the empty flasks are delivered by a pivoted gate assembly 66 to the jaw assemblies associated with the turret 42.

The various machine operations briefly outlined above may be carried out at the will of an operator by suitable manual control mechanism, in which case the machine may be regarded as being semi-automatic in its operation. It is within the purview of the present invention however to cause fully automatic cyclic machine operations under the control of suitable timing mechanism or interdependent sequence actuating mechanism. The present invention is not concerned with the particular manner in which sequential machine operations are initiated and, irrespective of the means whereby these operations are caused to follow one another, the essential features of the invention are at all times preserved.

The Combined Pattern Draw and Flask Centering, Supporting and Spinning Mechanism THE LIFT FRAME ASSEMBLY Referring now to FIGS. 1, 2 and 10, the lift frame assembly 10 involves in its general organization a supporting base 70 which is bolted as at 72 or is otherwise suitably mounted on the foundry floor 74 or other supporting surface and has projecting vertically upwardly therefrom a cylindrical standard 76 of appreciable height. In the upper regions of the standard 76 there is provided a pair of diametrically disposed rails 78 which extend vertically along the standard on opposite sides thereof. Gusset webs 80 are formed on the base 70 and lower regions of the standard 76 for reinforcing purposes. The standard 76 has formed thereon a pair of vertically spaced bosses 82 and 84 respectively, the boss 82 being disposed near the base 70 and the boss 84 being disposed at a region slightly below the lower ends of the rails 78. The boss 82 serves to support thereon the lower end of an elongated vertically disposed cylinder 86 which constitutes one of the principal elements of the previously mentioned piston and cylinder assembly 14. The upper end of the cylinder 86 is supported by the upper boss 84. A piston 88 is reciprocable in the cylinder '86 and has connected thereto a piston rod or plunger 90, the upper end of which is connected to the vertically shiftable lift and centering carriage 12. The opposite end regions of the cylinder 86 are provided with fluid ports 92 and 94 respectively which may be 'operatively connected through respective fluid lines 96 and 98 to a suitable control valve (not shown) which may be either manually operable or automatic and by means of which fluid under pressure is selectively applied to the ends of the cylinder for plunger extension and retraction purposes.

Still referring to FIGS. 1, 2 and 10, the vertically shift-able lift and centering carriage 12 may be in the form of a casting including a base portion 1(l01to which the upper end of the plunger is attached. An arm 102 extends vertically upwardly from the base portion and has a laterally turned bifurcated end 104 which straddles the standard 76 and carries a pair of rollers 1G6 designed to travel on the respective rails 78. An hyperbolic roller 108 is carried on a pin 110 which eX- tends across the bifurcations at the top of the arm 1G2 and is adapted to bear against the outer surface of the standard 76. The carriage 12 is thus constrained to move tractionally along the standard '76 under the influence of the plunger 90.

A horizontal arm 112 extends laterally from the base portion 190 of the carriage 12 and terminates in a hub 114 from which there extends radially outwardly a series of three spider arms 116. Each arm carries one of the previously mentioned centering rollers 22. Each roller is of generally frusto-conical design, the various rollers eing mounted on suspension pins 126 which depend from the outer ends of the respective arms 116. As will be described in greater detail presently, the centering rollers 22 are adapted, when the carriage 12 is in its lowered position, to straddle the circular flanged end 24 of a flask 20 undergoing ramming at the ramming station R.

THE INNER CORE PATTERN AND THE SUPPORTING MEANS THEREFOR Referring now to FIGS. 9 and 10, the inner core pattern 28, which will hereinafter be referred to as the mandrel, is in the form of a cylindrical member, the upper rim of which is recessed as at 122 to provide a seat for a centering plate 124. A shaft 126 extends upwardly from the central regions of the plate 124 and projects into a central bore 128 which is formed in the hub 114 of the lift carriage 12. The upper end of the shaft 126 is reduced as at 130 and receives thereover a lift collar 132. A bearing assembly 134 seats on the collar 132 and a retention nut 136 is threadedly received on the extreme upper end of the reduced portion 130 of the shaft 126. The underneath side of the hub 114 is recessed as at 138 to provide a gland for a seal assembly 140. The bore 128 is provided with an internal shoulder 142 which underlies the lift collar 132 and constitutes a lift shoulder by means of which the rotatable mandrel 28 is elevated and lowered bodily with the carriage 12. A cover plate 144 closes the upper end of the bore 128 and is removably held in position by means of screws 146.

The Pattern Draw, and Flask Centering Supporting and Spinning .Mechanism Referring now to FIGS. 3 and 4 wherein the pattern draw and flask centering, supporting and spinning mechanism 32 is best illustrated, the lower end region of a flask 20 is shown as being operatively positioned on the upper surface 148 of the rotary spinning table 16, the various flasks being successively delivered to and removed from the table by the rotary flask and mold transfer and upending mechanism 40 (FIG. 1). The spinning table 16 is in the form of a casting including a tubular sleeve portion 154 from the upper portion of which the table proper 156' extends radially outwardly. The sleeve portion 154 is rotatably supported by means of upper and lower bearing assemblies 157 and 159 respectively, upon a vertically shiftable but nonrotatable pedestal 153, the lower end of which is provided with a pedestal base 169 which is bolted as at 162 to a crosshead 164. A cylindrical sheet metal apron 166 depends from the peripheral regions of the table roper 156 and serves to shield the pedestal 154, as well as certain other instrumentalities associated with the assembly 32 and which will be described in detail presently.

Still referring to FIGS. 3 and 4, and additionally to FIG. 5, the crosshead 164 extends between and serves to operatively connect a pair of vertically reciprocable cylinder units 168, each unit constituting a principal component of one of the previously mentioned piston and cylinder assemblies 34. Each assembly 34 involves in its general organization a cylinder proper 170, the upper end of which is secured in the crosshead 164 and the lower end of which is secured in a cylinder cap 172. The two cylinders 17% are vertically reciprocable in unison and they are guided in their vertical movements by a pair of stationary piston rods 174 which they surround. Each rod 174 carries in the medial regions thereof a piston 176. Fluid under pressure is adapted to be admitted to the opposite ends of each cylinder 170v 6 through fluid' ports 177 and 179, above and below the piston 176 respectively, by means of flexible fluid lines 17-3 and 186 leading from a suitable control valve (not shown) which, in turn, is operatively connected to a source of motive fluid. Tie rods 182 serve to connect the crosshead 164 and cylinder caps 172.

The lower ends of the stationary piston rods 174 are reduced as at 184 and these reduced portions are surrounded by bushings 186 which, in turn, are centered in pilot blocks 188 Welded as at 190 to a base plate 192. A cylindrical casing 194 is welded as at 195 to the base plate 192 and projects upwardly and extends in telescopic fashion into the lower open rim 196 of the skirt 166. An anchor ring 198 for the upper ends of the piston rods 174 is seated on the upper rim 260 of the casing 194 and is formed with a central opening 202 through which the lower region of the tubular sleeve portion 154 of the spinning table 16 is adapted to project. A pair of bushings 204 are mounted at diametrically disposed points on the anchor ring 198 and receive therein the upper ends of the respective piston rods 174.

The previously mentioned fluid motor 30 is of conventional design and no claim is made herein to any novelty associated with the same. It is deemed suflicient for purposes of disclosure and description herein to state that the motor 31) includes a cylindrical casing 210 having a rim flange 212 which is bolted as at 214 to the underneath side of the crosshead 164. Intake and exhaust fluid lines are designated at 216 and 218 respectively and, upon admission of motive fluid to the casing 210, the output shaft 220 of the motor is caused to rotate in the desired direction.

The motor shaft 220 is operatively connected through a flexible coupling assembly 222 (FIG. 3) to a shaft 224, the upper end of which is threaded as at 226 and threadedly receives thereon an alignment cone 228 for centering a pattern base member or hub pattern 230 on the table surface 148. The hub pattern is provided with a contoured surface 232 of any desired configuration, as for example, that of the lower hub or bell of a metal pipe section subsequently to be cast by a centrifugal casting process in the pipe molds undergoing formation in the spinning apparatus. The hub pattern 230 is concentric with the circular table 156 and during flask spin ning operations, the lower flanged end 18 of the flask 29' is centered about the hub pattern 230 by means of centering guides 234 (see also FIG. 4) disposed at equally spaced regions around the periphery of the table 198.

The Rotary Flask and M'old Transfer and Upending Mechanism THE TURRET MOUNTING AND DRIVE MEANS Referring now to FIGS. 6, 7 and 8 wherein the details of the rotary flask and mold transfer and upending mech anism 46 are best illustrated, the previously mentioned turret base 44 embodies a casting or frame 259 which may be generally of frusto-conical design and the upper rim of which is provided with an inturned supporting and bolting flange 252. A hollow tubular pedestal 254 of upwardly tapering design is provided with a flanged base portion 256 which is bolted as at 257 to the bolting flange 252.

The previously mentioned turret assembly 42 is comprised of two principal parts including a lower sleeve section 258 and an upper turret housing section 260, the two sections being bolted together as at 262. The lower sleeve section 258 surrounds the pedestal 254 and is rotatabiy supported thereon by means of upper and lower bearing assemblies 264 and 266 respectively. The lower flanged rim portion 267 of the tubular sleeve section 258 carries a dust cap ring or retainer 268 for a felt or other sealing ring 27 0 which bears against a cylindrical surface 272 of the pedestal 254. The upper end of the pedestal 254 has secured thereto by means of anchoring screws 274 a stationary bevel gear 276 having teeth 277 thereon and the axis of which extends vertically. The circumferential or arcuate extent of the gear 276 may be slightly in excess of 180. The function of the bevel gear 276 is to provide a fixed reaction member for the tractional drive of a second and intermeshing bevel gear 278 having teeth 279 thereon and the am's of which extends horizontally. This latter gear serves to impart rotational movements to a jawsupporting shaft 230 on which the previously mentioned jaw assemblies 46 and 48 are operatively mounted, all in a manner and for a purpose that will be made clear presently.

The turret assembly 42 is adapted to be rotated alternately in opposite directions throughout an angle of 180, each such 180 rotation constituting a machine cycle during which an empty flask is brought from the transfer station T to the ramming station while simultaneously a rammed flask 20 is moved from the ramming station to the transfer station. Accordingly, a drive shaft 282 projects upwardly through the fixed pedestal 254 and the upper end of the shaft carries a coupling member 284 which is splined as at 286 to the shaft and keyed as at 288 to an inwardly extending web 230 formed on the upper turret section 260.

The lower end of the vertical drive shaft 282 is operatively connected by means of a coupling assembly 292 to the vertical output shaft 234 of the previously mentioned fluid-actuated motor 54. The motor 54 is suspended by means of suitable bolts 296 from an internal frame web 298 associated with the same. Briefly however, the motor 54 includes a casing 300 of generally cylindrical design and providing an internal operating chamber 302 for a pivoted vane 304. The output shaft 294 extends vertically through the chamber 302 and the vane 304 is carried by and extends radially outwardly from the shaft within the casing 300 so as to make substantial sealing and sweeping contact with the inside cylindrical face of the casing 300. A relatively thick web 306 is formed internally on the casing 302 and extends radially inwardly and makes substantial sealing contact with the shaft 294. The pivoted vane 304 is designed to be swung within the casing 300 through an angle of 180 in opposite directions under the motivating influence of fluid under pressure admitted to the interior of the casing 300 through fluid lines 308 and 310 which communicate with the chamber 302 through respective fluid ports 312 and 314. Angular swinging movement of the vane 304 is limited in opposite directions by means of internal lugs or stops 316 and 318 formed on the casing wall.

The fluid lines 308 and 310 may be operatively connected to a suitable control valve (not shown) which, in turn, is connected to a source of the motive fluid under pressure. Thus, the ports 312 and 314 alternately may serve as fluid inlet and fluid outlet ports for alternate movement of the vane 304, and consequently of the output shaft 282 and turret assembly 40 in the opposite directions.

THE JAW ASSEMBLY MOUNTING AND DRIVE MEANS Still referring to FIG. 6, the upperr turret housing section 26%) includes spaced end walls 320 and 322, through which there extend aligned openings 324. The jaw-supporting shaft 280 extends horizontally through the housing section 260 and is rotatably journalled in the aligned openings 324 by means of respective bearing assemblies 326. Near the outer rims of the openings 324, suitable dust seal assemblies 328 are provided between the shaft 280 and end walls 320 and 322.

The shaft 280 is formed with a reduced section 330 and the bevel gear 278 is mounted on and keyed as at 332 to this reduced shaft section. The shaft 280 is further reduced as at 334 at the opposite ends thereof and these reduced end portions have operatively mounted thereon the respective jaw assemblies 46 and 48.

THE LAW ASSEMBLIES Referring now to FIGS. 1, 2 and 10, the two jaw assemblies 46 and 48 are substantially identical in construction and therefore it is believed that a description of one of them will sufiice for them both. Each jaw assembly is in the form of a jaw cradle 350 of generally U-shape configuration in longitudinal cross section and including a pair of parallel side plates 352 and 354 respectively (FIG. 1a), and a connecting web plate 356. The plate 356 is formed with a central circular opening 358 therein into which the distal end of the adjacent reduced portion 334 of the shaft 230 extends and in which opening it is secured by welding. Each side plate 352 and 354 is formed with a forwardly extending fixed jaw finger 360 which projects forwardly from one longitudinal edge of the side plate, the two jaw fingers 360 extending in parallelism and constituting in effect a composite fixed jaw which is opposed by the previously mentioned pivoted jaw fingers 50. These latter jaw fingers 50 have their base or proximate ends seated within recesses 364 provided in the respective side plates 352 and .354 and which are rigidly connected together by a transverse operating shaft 366. The ends of the operating shaft 366 are rotatably mounted in the two side plates 352 and 354. The operating shaft 366 has fixedly secured thereto in the medial regions thereof a torque arm 368, the distal end of which is adjustably and pivotally connected by a yoke 370 which is threaded on one end of a piston rod 372 associated with the previously mentioned piston and cylinder assembly 52. The other end of the rod 372 extends into a cylinder 374, an end of which is pivoted as at 376 to an ear 37 8 mounted on the web plate 356. The cylinder is provided with fluid ports 380 and 332 connected to respective flexible fluid lines 384 and 386 which may be operatively connected to a suitable control valve (not shown) by means of which motive fluid may be selectively directed to the piston and cylinder assembly 52. The two ports are disposed on opposite sides of a piston 388 within the cylinder 374, the latter being operatively mounted on the piston rod 372.

The inner opposed surfaces of the various jaw fingers 36% and 362 are curved to conform to the cylindrical outer surfaces of the flasks 20 undergoing transfer between the ramming station R and the transfer station T and vice versa. Thus it will be seen that upon selective application of motive fluid to the opposite ends of the cylinder 374 through the ports 380 and 382, rocking motion will be transmitted to the pivoted jaw fingers 362 for jaw opening and closing purposes in a manner and for a purpose that will be made clear presently.

The Flask Take-Ofl and Delivery Mechanism at the Transfer Station As best seen in FIGS. 1, 2 and 10, there is provided at the transfer station T a flask take-off and delivery mechanism which includes the previously mentioned transfer carriage and delivery gate 66.

FLASK' TAKE-OFF MECHANISM The flask take-off mechanism includes the transfer carriage E0 and rails 62. The transfer carriage is comprised of two spaced apart yoke arms 400 having their lower proximate ends secured to a horizontal rock shaft 402 which extends between a pair of base supports or standards 404. A transverse shaft 406 is connected at its ends to the yoke arms 4'00 and constrains these arms to move in unison. A piston and cylinder assembly 408 including a cylinder 410 and a piston 412 has the cylinder component thereof pivoted as at 414 to a fixed reaction member 416 while the piston component is provided With a piston rod 413, the distal end of which is pivotally connected to the shaft 406. The cylinder is provided with fluid ports 426 and 423 at the opposite end regions thereof which are connected to respective fluid lines 430 and 432. These latter fluid lines may be operatively connected to a control valve (not shown) for selective admission of fluid to the opposite ends of the cylinder 410.

The transfer carriage is movable between the advanced position wherein it is shown in FIG. 1 and the retracted position wherein it is shown in FIG. 10. In its advanced position, the cradle 58 underlies one of the clamping jaw assemblies 46 or 48, as the case may be, at the transfer station T and is in a position to receive by gravity from the jaw assembly a discharged flask 20. In its retracted position the yoke arms 4%!) which cooperate to make up the cradle 69 are adapted to engage respective limit stops 434 while the cradle portion 58 of the transfer carriage overlies an extreme end region of the rails 62 in such a manner that the flask carried by the cradle will be deposited on the rails 62 with the two flanges and 27 straddling the rails as shown in FIG. 2 for subsequent tractional rolling movement of the flask along the inclined rails to the remote spinning and pouring station.

THE JA'W LOADING MECHANISM The jaw loading mechanism is best illustrated in FIGS. 1, 2 and 10 and includes the previously described rails 64 and the pivoted gate assembly 66. The gate assembly 66 is comprised of a pair of spaced parallel gate fingers 436 which are connected together for movement in unison by a transverse connecting bar 450 and which are pivoted as at 451 adjacent but a slight distance inwards of their proximate ends to the end regions of the respective rails 62'. The bar 450 carries an attachment lug 452 by means of which the bar may be operatively connected to an actuating piston and cylinder assembly 454. Accordingly, the cylinder 456 of the assembly 454 is pivoted as at 457 to a fixed reaction point 459. A piston which is reciprocable in the cylinder 456 has its free end pivotally connected as at 462 to the attachment lug 452. The cylinder is provided with fluid ports 464 and 466 which are connected through fluid lines 463 and 476 to a suitable control valve by means of which motive fluid is selectively applied to the ports 464 and 466.

The gate fingers 436 are adapted normally to be maintained in the elevated full line position wherein they are shown in FIG. 1. The gate fingers 436 are of arcuate design, the are being of relatively long radius or curvature. When the fingers 436 are thus elevated, the distal ends thereof are maintained above the level of the rails 62 so that the gate member 66 will act as a limit stop to prevent any flask or flasks supported on the rails from running oif the end of the rails. In the lowered position of the fingers 436, the ends of the latter register with the ends of the pivoted jaw fingers 362 as shown in FIG. 10 when the latter are in their open position so that the foremost flask 29 on the rails 64 may travel along the gate member and roll down the inclined upper edges thereof and enter the open jaw structure 46 or 48 as the case may be. At the same time, the extreme proximate end regions 472 of the gate fingers 436 will become slightly elevated above the level of the forward ends of the rails as and serve as a stop for the foremost flask 20 in the rails.

Operation of the Apparatus The operation of the apparatus may be described almost in its entirety with reference to FIGS. 1 and 10. A stationary sand slinger, a fragment of which has been designated at 489 in FIG. 1 and which is of conventional design, is adapted to deliver sand in the form of wads or slugs to the cavity which exists between the cylindrical wall of the flask 29 and the mandrel 28. These wads are delivered to the flask after the flask and pattern have been properly positioned and centered upon the upper surface of the table proper 156 and while the table is being rotated under the influence of the fluid motor 30. The speed of rotation of the flask 26 will control the density of the sand mold formed in the flask.

Assuming that the jaw asembly 46 is disposed at the rannnin station R and that the jaw assembly 425 is disposed at the transfer station T during a given spinning operation, the pivoted jaw fingers 50 of the assembly 48 is maintained in their open position until such time as the spinning operation has been completed. During the spinning operation, the rotating flask is loosely nested or cradled, so to speak, within the confines of the jaw assembly but it is not engaged or otherwise restrained against rotation by the assembly. Immediately thereafter motive fluid is supplied to the piston and cylinder assembly 52 to close the jaws and cause the vertically disposed flask 25 to be firmly gripped thereby.

During the spinning operation just described, the jaw assembly 48 at the transfer station has its jaw axis extending horizontally so that when the pivoted jaw fingers 362 are in their open position the jaws will be conditioned to receive therein an empty flask 20 by gravity from the rails 64. The two centering flanges 25 and 27 on the flask 20 straddle the rails 64 and prevent endwise movement of the flasks on the rails. The jaw assembly 48 may be loaded conveniently during the spinning operation at the ramming station R and, accordingly, the piston and cylinder assembly 454 is supplied with motive fluid in such a manner as to cause the pivoted gate assembly 66 to become lowered to the position wherein it is shown in full lines in FIG. 10 with the distal ends of the jaw fingers 50 and gate fingers 436 in substantial register. At such time, the foremost flask 20 of the series of flasks carried on the rails 64 will roll by gravity from the inclined gate fingers to the jaw fingers and, immediately thereafter, motive fluid is supplied to the piston and cylinder assembly 52 to cause the jaw fingers 362 to close and elevate the flask 20 into the jaw cradle while at the same time the flask will be firmly gripped by the jaws.

After the jaw assembly 48 has thus been loaded at the transfer station T and the spinning operation at the ramming station R has been completed, the fluid motor 54 is energized in such a manner as to rotate the turret assembly 42 in a counterclockwise direction as viewed in FIG. 2 throughout an angle of 180 and cause the jaw assembly 43 to move bodily from the transfer station T to the ramming station, while at the same time the jaW assembly 46 is moved bodily from the ramming station to the transfer station. During such rotation of the turret assembly 42, the rotatable bevel gear 278 on the horizontal jaw-supporting shaft 230 will ride tractionally on the fixed intermeshing bevel gear 276 which has twice the number of teeth 277 thereon than the number of teeth on the gear 278 and describe an angular movement of while the turret' describes an angular movement of 180, thus causing a complete upending of the horizontal jaw assembly by the time it arrives at the ramming station R. The fixed gear 276 thus functions in the manner of a stationary toothed arcuate rack, while the gear 278 functions as a cooperating pinion. Upon arrival of the loaded jaw assembly 48 at its home position at the ramming station, the axis of the flask carried thereby will extend vertically and, as shown in FIG. 10, the flask will be maintained in an elevated position above the level of the spinning table 16 which, at that time, is in its lowermost position. The lower end of the mandrel 28 which is supported by the vertically shiftable lift and centering carriage 12 will assume an elevated position above the level of the upper end of the flask 20 with the mandrel 28 poised, so to speak, for subsequent descent into the flask. In this position of the flask 2d, the axes of the spinning table, the flask and mandrel are in vertical alignment.

After the flask 26 carried by the jaw assembly 48 has been brought to its final position at the ramming station R, fluid is supplied through the fluid lines 178 to the ports 177 associated with the hydraulic piston and cylinder assemblies 168. The admission of fluid to the upper ends of the cylinders 176 above the pistons 176 associated therewith will cause the previously lowered cylinders to become elevated to the position in which they appear in FIG. 3. Such elevation of the cylinders will cause the crosshead 164 to become elevated and the latter, acting through the pedestal 158, will cause the spinning table 16 to move into operative register with the lower flanged 1 I end 18 of the vertically disposed flask 26 carried by the jaw assembly 48, the centering guides 234 serving to maintain the end 18 centered upon the table proper 156.

As soon as the spinning table and flask have been thus moved into operative register, fluid under pressure is supplied to the port 94 through the fluid line 98 to drive the piston 88 in its plunger 99 downwardly to effect lowering of the lift carriage 12, and consequently of the mandrel 28. The mandrel is thus lowered into the upper end of the flask 20 and the alignment cone 228 causes the lower end of the mandrel to become seated and centered upon the hub pattern 230 as shown in FIG. 3. In this position of the parts, the upper flanged end 24 of the flask 20 is centered between the three rollers 22 preparatory to initiation of the flask spinning operation.

Upon admission of fluid to the hydraulic motor 30 through the intake fluid line 216, spinning operations will be initiated, the output shaft 2220 serving to drive the spinning table 16 through the coupling assembly 222 and shaft 224. Wads of sand are fed to the flask from the slinger 486 in the manner previously described and, after the sand mold has been formed, spinning operations are terminated and fluid is supplied to the port 92 of the piston and cylinder assembly 14 through the fluid line 96 to cause the carriage 12 to be elevated, thereby raising the mandrel 28 and effecting the upper pattern draw operation. Similarly, fluid is supplied to the ports 179 of the piston and cylinder assemblies 168 through the fluid lines 180 to lower the cylinders proper 170 and crosshead 164, thus lowering the spinning table 16 and effecting the lower pattern draw operation and freeing the flask with the mold therein for conduction by the mechanism 40 to the transfer station T.

To effect such transfer, fluid is supplied to the piston and cylinder assembly 52 to cause the movable jaw 59 to close upon the flask body between the flanges 25 and 27, after which the fluid motor 54 may be operated in the manner previously described to rotate the turret 42 throughout a 180 increment of turning movement thus causing the jaw assembly 48 with the flask 20 carried thereby to be conducted to the transfer station while at the same time, due to the previously described cooperation between the intermeshing fixed and movable bevel gears 276 and 278 respectively, the shaft 280, and consequently the jaw assembly 48 will be turned about a horizontal axis through an angle of 90 to deliver the flask 20 to the transfer station T in a horizontal position.

It will be understood, of course, that during each indexing operation of the turret 40, whether the motion thereof be clockwise or counterclockwise, as viewed in FIG. 2, an interchange of the jaw assemblies 46 and 48 between the transfer and ramming stations will take place. Movement of either jaw assembly 4-6 or as from the trans fer station to the ramming station is accompanied by an upending of the flask 20 carried in such jaw assembly. Conversely, movement of either jaw assembly 46 or 48 from the ramming station to the transfer station is accompanied by a declination of the flask 20 and its contained mold carried thereby.

As soon as the flask 20 has thus been returned to the transfer station fluid is supplied to the piston and cylinder assembly 52 to open the jaw finger S and release the flask 20 to the transfer carriage 60 which, at this time assumes the position in which it is shown in FIG. 1 in proximate register with the jaw assembly 18.

Inasmuch as a full description of the operation of the transfer mechanism at the transfer station T has previously been rendered, it is believed that the nature, operation and many advantages of the herein described flask handling and mold forming apparatus will be readily understood without further detailed description. The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification since the disclosure made herein is somewhat schematic in its representation and various changes n the details of construction and in the mode of operation may be resorted to without departing from the spirit of the invention. For example, while the turret assembly 42 has been described herein as being oscillatable in that successive indexing operations thereof throughout an angle of are accompanied by a reversal in the direction of turning movement of the turret, it is within the scope of the invention to effect unidirectional indexing movements of the turret assembly, utilizing full instead of partial bevel gears in the turret housing, in which case rotary slip connections for the various flexible fluid lines involved will be required. Other modifications of the structural devices embodied in the apparatus as disclosed herein are contemplated within the purview of the present invention while, similarly, variations in the procedural details of the disclosed method by means of which the invention is carried out are contemplated. For example, the introduction of excess sand into the flask at the namming station and the striking off of the sand so that the same will be flush with the top of the pattern prior to closing of the flask 20 preparatory to the spinning operation at the ramming station are conventional practices which may be resorted to if necessary without affecting the essential features of the process. Only insofar as the invention has particularly been pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what I claim as new and desire to secure by Letters Patent is:

1. In an apparatus for the production of molds for use in the centrifugal casting of hollow cylindrical metal objects, in combination, means establishing a spinning and pouring station, a ramming station, and an intermediate transfer station, a horizontally disposed vertically shiftable spinning table mounted for rotation about a vertical axis at the ramming station, a base pattern mounted on said table, a vertically shiftable centering and lifting head for a core pattern at said ramming station in vertical alignment with the spinning table, a core pattern rotatably mounted on said lifting head and movable bodily therewith during vertical movements of the latter, said table and lifting head being capable of relative approaching and retracting movement in opposed relation for cooperation with cylindrical shell flasks which are successively positioned therebetween, power actuated means for shifting said lifting head vertically, power actuated means for shifting said table vertically, a first inclined ramp extending between the spinning and pouring station and the transfer station and having its lower delivery end terminating at said latter station, said ramp being adapted to receive empty cylindrical flasks thereon in a horizontal position at the spinning and pouring station for conduction therealong by a rolling action under the influence of gravity to the transfer station, a second inclined ramp extending between the spinning and pouring station and the transfer station and having its lower delivery end terminating at said latter station, said second ramp being adapted to receive mold-containing flasks thereon in a horizontal position at the transfer station for conduction therealong by a rolling action under the influence of gravity to the spinning and pouring station, a turret mounted for rotation about a vertical axis between the transfer and ramming station, a pair of flask-receiving and gripping jaws carried by said turret and rotatable about a common horizontal axis between positions wherein the axes of the jaws extend horizontally and positions wherein the axes of the jaws extend vertically, said jaws being capable of independent opening and closing movements for flask-releasing and flask-gripping operations respectively, said turret being operable, upon rotation thereof throughout an angle of 180 to move one jaw from the transfer station to the ramming station and to simultaneously move the other jaw from the ramming station to the transfer station, means operatively connecting said jaws for rotational movements in unison, each of said jaws assuming a position wherein its axis extends horizontally when the other jaw is so disposed that its axis extends vertically and vice versa, means constraining each jaw to assume a position wherein its axis is in operative vertical register with the lifting head and table when such jaw is disposed at the ramming station and to assume a position wherein its axis is in horizontal register with the delivery end of said first mentioned ramp when such jaw is disposed at the transfer station, power actuated means for rotating said turret, power actuated means for selectively actuating said jaws, a transfer carriage disposed at said transfer station for receiving flasks discharged by said jaws at said latter station and delivering the same to said second ramp, said transfer carriage being movable between a position wherein it is in receiving register with a jaw disposed at the transfer station and a position wherein it is in delivery register with the receiving end of said second ramp, and power actuated means for moving said transfer carriage.

References Cited in the file of this patent UNITED STATES PATENTS 1,550,514 Dimick Aug. 18, 1925 2,850,775 Northington et a1. Sept. 9, 1958 2,859,497 Winter Nov. 11, 1958 2,879,563 Ewing Mar. 31, 1959 

